Cutter bars include a finger bar which has a plurality of reaping fingers. A knife reciprocates relative to the finger bar. The knife includes a knife bar which has several blades. The blades form cutting edges. Counter cutting edges are formed by the reaping fingers and interact with the blades.
The blades have a generally triangular base. During the cutting procedure, the harvesting goods, due to the reciprocating movement of the knife, are pressed by the blades against the reaping fingers and cut. Accordingly, a scissor-like cutting movement is produced. Thus, each individual blade is pushed to the back, when viewed in a working direction, by the cutting load. Thus, a knife supporting guide, relative to the finger bar, is necessary to hold the knife in its position relative to the finger bar. Such a guide is shown in DE 198 50 261 A1. Here, the cutter bar has a guide plate mounted on the finger bar. The guide plate forms a guide face extending in the direction of the movement direction of the knife and is facing the knife. The knife is supported, when viewed in a working direction, to the rear by the knife bar on the guide face of the guide plate. While the knife bar reciprocates, the guide plate is rigidly mounted on the finger bar. The knife is pressed independent of the cutting force more or less strongly against the guide plate. The cutting force can increase due to the harvesting good, which is difficult to cut, or due to dull knife blades. Thus, increased frictional forces are active between the knife bar and the guide plate. This leads, especially with sandy and corundum-containing soil, to a larger wear on the knife bar and on the guide plate. Furthermore, besides the driving power necessary for cutting the harvesting goods, a significant part of the driving power is necessary for the reciprocating movement of the knife. The necessary driving power to move the knife is often higher than the necessary driving power for the cutting process.
In CH 148 390 the frictional force is reduced by a roller guide. The guide plates have recesses on which the cutter bar rollers are rotational mounted. The knife is supported, when viewed in the working direction, to the rear on the rollers and is guided by the guide plates. However, friction is still produced between the knife and the guide plates.